Pokémon Ruby and Sapphire/Seafloor Cavern — StrategyWiki

Seafloor Cavern is a subterranean cave deep beneath the waves of Route 128. The cavern is somewhat maze-like, and constantly requires the use of Rock Smash and Strength

Pokémon Ruby and Sapphire/Seafloor Cavern — StrategyWiki

Seafloor Cavern - Pokemon Omega Ruby and Alpha Sapphire Guide - IGN

Pokéarth - Hoenn - Seafloor Cavern

15 Hidden Locations in Pokémon Ruby & Sapphire That Only Experts Found

Pokémon Ruby and Sapphire/Scorched Slab — StrategyWiki

Pokemon Ruby, Saphire and Emerald - Seafloor Cavern Puzzle

Pokémon Ruby and Sapphire/Seafloor Cavern — StrategyWiki

Pokéarth - Hoenn - Seafloor Cavern

Poke Cave

Pokemon Sapphire - Part 37 - The Seafloor Cavern